TRANSPARENT · DATA-MINIMISING
Privacy policy
This notice explains clearly and fully which personal data is processed when you visit and use Clevercalc. It applies to every language version of the website and also serves as the comprehensive privacy notice required under applicable Mexican data protection law.
Last updated: 4 September 2026Values entered into calculators are generally processed only in your browser.
Clevercalc does not use advertising, analytics profiles or marketing trackers.
You can delete local favourites, history and saved results through your browser data at any time.
1. Controller
The person responsible for processing personal data on Clevercalc is:
Daniel Behrendt FeilingBv. De los Lagos 201Punta CascattaTercera Sección de Santa Clara OcoyucanOcoyucan, Puebla 72850MéxicoEmail: daniel.beh92@yahoo.deYou may send privacy enquiries and requests to exercise your rights to the email address above.
2. Scope and data categories
Clevercalc processes only data needed to operate the website, provide features you choose or answer a contact request. This may include technical connection data, locally stored preferences, data from an optional currency request and information you send by email.
No user accounts are created, no payment data is collected, and no personal data is used for advertising, profiling or automated decisions. Clevercalc does not request sensitive personal data for server-side processing.
3. Calculators, PDF feature and Koda
Values entered into calculators — including health, fitness, finance or property calculator details — are normally processed exclusively by code in your browser. They are not sent to the operator or hosting provider and are not stored permanently. The only exception is the rate request described in the “Currency calculator” section.
Individual result PDFs and combined PDFs are generated exclusively in your browser. No calculator values are sent to an external PDF service. Only when you select “Add to PDF collection” does Clevercalc store the displayed inputs, results, calculator name and time locally on your device. You can remove individual entries at any time under “My results”.
Koda is a free, local, rule-based assistant for calculator search, simple arithmetic and short conversations. Koda does not use the OpenAI API or another external AI chat service. Your Koda messages remain in the memory of the open page, are not transmitted and disappear when the page is reloaded or closed.
Legal bases at a glance
Website access and hosting
Delivery, stability and security
Necessary service and legitimate interests; GDPR Art. 6(1)(f), where applicable
Local preferences
Remember language, favourites, history, PDF collection and Koda notice
Technically necessary functionality requested by the user; German TDDDG section 25(2)(2), where applicable
Currency lookup
Current reference rates requested by the user
Explicit user request and legitimate interests; GDPR Art. 6(1)(f), where applicable
Email contact
Answer enquiries and, where relevant, prepare a contract
GDPR Art. 6(1)(b) or (f), where applicable; legal obligations may rely on point (c)
4. Local storage and cookies
Clevercalc stores your selected language and the identifiers of your favourites and recently used calculators in your browser's local storage. Only when you explicitly add a result to the PDF collection are the displayed inputs, result, calculator name and time also stored locally. Session storage records only whether Koda's welcome message has already appeared.
These entries enable features you expressly request. You can remove results individually under “My results”; all local entries can also be deleted through your browser's website data. If storage is blocked, favourites, history, language memory, the PDF collection or the Koda notice may not work fully.
Clevercalc does not set its own advertising, analytics or tracking cookies. The hosting platform may use technically necessary cookies or similar technologies for security, access protection and website delivery.
5. Hosting by ChatGPT Sites
The website is hosted through ChatGPT Sites by OpenAI. Under the ChatGPT Sites terms, the contracting entity for operators outside the European Economic Area and Switzerland is OpenAI OpCo, LLC, USA. OpenAI processes hosting data as a processor to deliver, maintain and secure the website.
Technical log, usage and device data may be generated automatically when the site is accessed. This can include the IP address, time, requested page, browser and device type, operating system, referrer — if supplied by the browser — and status or security signals. It is used only for delivery, stability, troubleshooting, abuse prevention and security. Clevercalc does not create its own advertising or usage profile from it.
6. Currency calculator and Frankfurter
Only when you start a currency conversion does your browser connect to Frankfurter's public API. Only the source and target currency codes are transmitted. The amount you enter remains in your browser and is multiplied there by the retrieved reference rate. As with any direct internet connection, the service also technically receives connection data such as your IP address and standard browser headers.
Frankfurter states that the API itself does not collect personal data; however, the public service runs behind Cloudflare, which may collect basic information for analytics and security. Clevercalc receives only the reference rate and rate date and does not create a user profile from it. If you do not want this connection, do not use the currency calculator; all other calculators remain unaffected.
7. Contact by email
If you contact us by email, we process the information you voluntarily provide, particularly your email address, name, message content and any attachments. It is processed to handle and answer your request and, where necessary, to prepare or perform a contractual relationship.
Communications are processed through the operator's Yahoo email service. Please do not send health data, payment data, identity documents or other particularly confidential information by email unless strictly necessary and agreed in advance.
8. Share and copy functions
The “Share calculation” feature uses your device's native share function where available. Only when you select it does your browser pass the page title and link to the service you choose. If native sharing is unavailable, only the link is copied to the clipboard. Clevercalc does not independently transmit data to social networks.
9. Recipients and international processing
Recipients of personal data may include — only where necessary — OpenAI and its subprocessors for hosting and security, Frankfurter and its infrastructure provider Cloudflare during a currency request, the email provider used, and public authorities where legally required.
Because the infrastructure is international, processing may take place particularly in Mexico, the United States and other countries. Where required, processor relationships and international transfers rely on the providers' contractual safeguards and guarantees available under applicable law. Personal data is not sold, rented or disclosed for third-party advertising. No non-essential marketing transfers take place, so no separate consent for such transfers is currently requested.
10. Retention
Local browser data, including an explicitly saved PDF collection, remains on your device until you remove it or reset website data or the browser. Koda's session notice generally ends with the browser session. Clevercalc does not maintain its own database of calculator values, favourites, PDF results or chat messages.
Technical hosting data is processed only for as long as needed for delivery, security, abuse prevention and contractual or legal obligations; specific periods depend on the hosting provider's settings and requirements. Email communications are deleted after the request is completed unless legal retention duties or legitimate reasons require further storage.
11. Your privacy rights
Depending on applicable law, you may request access, rectification, erasure or cancellation, restriction of processing, data portability and objection. You may withdraw consent at any time for the future. Under Mexican law, you particularly have the ARCO rights of Acceso, Rectificación, Cancelación and Oposición, as well as the right to limit the use or disclosure of your data.
Send your request with the subject “Privacy” or “Privacidad” to the email address above. Include your full name, a way for us to reply, the right you wish to exercise, the data concerned and any information that helps locate it. Where necessary, we may request suitable proof of identity; unnecessary details may be redacted. Requests are handled free of charge and within statutory time limits unless applicable law permits otherwise.
You also have the right to complain to the competent data protection authority. This may be the competent Mexican privacy authority or, where the GDPR applies, an authority in the EU Member State of your residence, workplace or the alleged infringement.
12. Security and minors
The website is transmitted over encrypted HTTPS. Local calculations and data minimisation deliberately reduce the amount of information transferred. No internet service can guarantee absolute security, however.
Clevercalc is not designed to collect personal data from children. Minors should not send personal or confidential information by email and should use the website only with the consent or supervision of a parent or guardian where required by the law of their residence.
13. Changes to this notice
This privacy policy will be updated if features, providers or legal requirements change. The current version is always published on this page, and the date at the top shows the latest revision. If optional analytics, advertising or other consent-based technologies are added in future, this notice will be updated first and consent will be obtained where required.